import * as stream from 'stream';
import { Transform, TransformCallback } from 'stream';

/**
 * Options for MD5Stream constructor
 */
interface MD5StreamOptions {
    /**
     * Custom add32 function for compatibility testing
     */
    add32?: (x: number, y: number) => number;
}
/**
 * MD5Stream - Node.js Transform stream for computing MD5 hashes
 *
 * Usage example:
 * ```ts
 * import fs from 'fs';
 * import { MD5Stream } from 'pure-md5';
 *
 * const stream = new MD5Stream();
 * stream.on('md5', (result) => {
 *   console.log('MD5:', result.digest);
 *   console.log('Bytes:', result.bytesProcessed);
 * });
 *
 * fs.createReadStream('file.txt').pipe(stream);
 * ```
 */
declare class MD5Stream extends Transform {
    private state;
    private add32;
    private readonly initialMD5State;
    private readonly bufferCapacity;
    private buffer;
    /**
     * Create new MD5Stream instance
     * @param options - Stream options
     */
    constructor(options?: MD5StreamOptions);
    /**
     * Process data chunk and update MD5 state
     * @param chunk - Data chunk to process
     * @param callback - Callback to signal chunk processing complete
     */
    _transform(chunk: Buffer, _encoding: BufferEncoding, callback: TransformCallback): void;
    /**
     * Process the current buffer as a complete block
     */
    private _processBufferBlock;
    /**
     * Finalize MD5 computation and emit result
     * @param callback - Callback to signal flush complete
     */
    _flush(callback: TransformCallback): void;
    /**
     * Get current MD5 state (for debugging/testing)
     * @returns Current internal state
     */
    getCurrentState(): {
        state: number[];
        bytesProcessed: number;
    };
    /**
     * Get bytes processed so far
     * @returns Number of bytes processed
     */
    getBytesProcessed(): number;
    /**
     * Reset the stream state
     * Note: This resets the internal MD5 state but not the stream's ended state.
     * For full stream reset, use destroy() and create a new instance.
     */
    reset(): void;
    /**
     * Static method to create MD5Stream from existing readable stream
     * @param source - Source readable stream
     * @param options - MD5Stream options
     * @returns Object containing stream and result promise
     */
    static fromStream(source: stream.Readable, options?: MD5StreamOptions): {
        stream: MD5Stream;
        result: Promise<MD5Result>;
    };
}
/**
 * Factory function to create MD5Stream instance
 * @param options - MD5Stream options
 * @returns New MD5Stream instance
 */
declare function createMD5Stream(options?: MD5StreamOptions): MD5Stream;
/**
 * Result type for MD5 computation
 */
interface MD5Result {
    /**
     * MD5 hash as hex string
     */
    digest: string;
    /**
     * Number of bytes processed
     */
    bytesProcessed: number;
}
/**
 * Pipe through MD5 stream helper
 * @param this - MD5Stream instance
 * @param source - Source readable stream to process
 * @returns Promise with MD5 result
 */
declare function pipeThroughMD5(this: MD5Stream, source: stream.Readable): Promise<MD5Result>;
/**
 * Static method to create MD5Stream from existing readable stream
 * @param source - Source readable stream
 * @param options - MD5Stream options
 * @returns Object containing stream and result promise
 */
declare function fromStream(source: stream.Readable, options?: MD5StreamOptions): {
    stream: MD5Stream;
    result: Promise<MD5Result>;
};

export { type MD5Result, MD5Stream, createMD5Stream, fromStream, pipeThroughMD5 };